Key for an axial tumbler type lock



M y 1967 w. J. KERR 3,320,783

KEY FOR AN AXIAL TUMBLER TYPE LOCK Filed Dec. 9, 1966 INVENTOR.

WILLIAM J. K ERR United States Patent 3,320,783 KEY FOR AN AXIAL TUMBLER TYPE LOCK William J. Kerr, Glenview, 113., assignor to Chicago Lock Co., Chicago, 111., a corporation of Illinois Fiied Dec. 9, 1966, Ser. No. 600,551 3 illairns. (Cl. 7tl4il1) The present invention relates to a key for an axial tumbler type lock of the particular type which is shown and described in United States Patent No. 3,276,796, granted to me on Aug. 23, 1966, and entitled, Tamper- Proof Axial Tumbler-Type Lock. The key which constitutes the subject matter of the present patent application possesses :bittings which are of a functional nature over and beyond the functional nature of conventional keys which are designed for use in connection with conventional axial tumbler type locks. The bittings of such conventional keys are designed for one purpose only and that is to depress the axially extending, annularly arranged split tumblers of the looks so that the transverse splits thereof are in transverse register to the end that the proper keys, together with the rotatable portions of the lock cylinders, may be turned for locking or unlocking purposes. The bittings of the key of this patent application are possessed of a dual function, namely, the usual tumbler-depressing function and, additionally, the application of torque to the rotatable portion of the lock cylinder. The manner in which this second function is accomplished will become readily apparent as the nature of the invention is better understood from a consideration of the following detailed description or specification.

In the accompanying single sheet of drawings forming a part of this specification, one illustrative embodiment of the invention is illustrated in detail.

In these drawings:

FIG. 1 is a perspective view of a key constructed in accordance with the principles of the present invention;

FIG. 2 is a slightly enlarged transverse sectional view taken on the vertical plane indicate-d by the line 2-2 of FIG. 1, and in the direction of the arrows;

FIG. 3 is a slightly enlarged transverse sectional view taken on the vertical plane indicated by the line 33 of FIG. 1, and in the direction of the arrows;

FIG. 4 is a fragmentary cylindrical sectional view taken on the vertical plane indicated by the line 4-4 of FIG. 1;

FIG. 5 is a fragmentary longitudinal sectional View taken on the horizontal plane indicated by the line 55 of FIG. 1, and in the direction of the arrows;

FIG. 6 is a perspective view of an axial tumbler type lock of which the key of FIGS. 1 to 5 is a counterpart;

FIG. 7 is a fragmentary perspective view of the lock and key, showing the key projected or inserted into the lock cylinder, it being understood that in this particular view, the lock cylinder is shown in phantom dotted lines in the interests of clarity and in order more clearly to reveal the nature of the invention; and

FIG. 8 is a longitudinal sectional view taken on the vertical plane indicated by the line 88 of FIG. 6-, and in the direction of the arrows, portions of the lock cylinder and the key being shown in elevation.

Referring now to the drawings in detail and in particular to FIG. 1, a key embodying the principles of the present invention is designated in its entirety by the reference numeral 110. The details of this key will be set forth presently, but in order to insure a more comprehensive understanding of the function of the key 110*, it is deemed necessary that a general understanding of the lock which is operated by the key be attained. Such a lock is illustrated in FIGS. 6, 7 and 8, corresponds to that of said Patent No. 3,276,706, and is designated in its entirety by the reference numeral 10. The lock is a Patented May 23, 1967 special form of axial tumbler type lock wherein the associated split pin tumblers 12 are arranged in an annular series around, and extend parallel to, the central longitudinal axis of the lock cylinder 14. For a comprehensive understanding of the nature of the lock 10, reference may be had to said Patent No. 3,267,706, but for purposes of discussion herein, the disclosure of the lock in FIGS. 6, 7 and 8 is one which is calculated best to illustrate the cooperation of the lock 10 with the key 110.

The lock cylinder 14 encloses a two-part barrel assembly consisting of a sleeve-like rotatable part 16 and a sleeve-like fixed or non-rotatable part 18. The fixed part 18 of the two-part barrel assembly is located in front of the rotatable part 16 and is maintained within the cylinder by means of a radially extending pin 20. Throughout this description, directional references to either the key or the lock 10 will be made on the basis that the key is adapted to he thrust forwardly and endwise into the lock cylinder in connection with locking and unlocking of the lock, and withdrawn rearwardly therefrom. As best shown in FIG. 8, the front end of the lock cylinder 16 is provided with an enlarged head portion 22.

Each of the split pin tumblers 12 consists of a front driver pin 26 and a rear spring-pressed follower pin 28, and as previously pointed out, said tumblers are arranged in an annular series about the axis of the lock cylinder 14. The front driver pins 26 and the rear spring-pressed follower pins 28 of the pin tumblers are slidable longitudinally in respective bores 30 and 32 in the rotatable and nonrotatable parts 16- and 18 of the barrel assembly of the lock. The tumblers 12 are adapted to be displaced by certain shoulders on the key 110', and when they are so displaced that all of the joints or splits 34 between the adjacent ends of the rotatable driver pins 26 and the nonrotatable follower pins 28 are in register with the interfacial plane between the two barrel assembly parts 16 and 18, the rotatable part 16 may be turned within the lock cylinder 14 by means of a special torque-applying fin on the key 110, all in a manner that will be made clear presently.

The enlarged head portion of the lock cylinder 14 is provided with an inwardly extending front wall or flange 40 (see FIG. 6) which constitutes a protective plate and has a central opening 42. The latter is interrupted by a series of radial slots 4-4, adjacent slots being preferably equiangularly spaced from each other so that the subtended angles are equal, seven such slots being disclosed herein for exemplary purposes. A lock shaft 46 projects completely through the lock cylinder 12 and the two parts 16 and 18 of the barrel assembly and the extreme forward region of this shaft constitutes a pilot post 48 which cooperates with the key 110 in a manner that likewise will be made clear subsequently. The rear end portion of the lock shaft 46 projects rearwardly beyond the rear rim or end of the cylinder 12 and carries the usual radially extending locking flange 50 which turns with the shaft and is adapted to cooperate with a fixed locking cam (not shown) that is associated with a door or other structure, the closure of which is protected by the lock and key assembly.

The forward end region of the rotatable part 16 of the barrel assembly is formed with a tubular sleeve portion 52 the forward rim of which is provided with an irregularly shaped notch therein, the notch including a forward wide portion 54 and a rear narrow portion 56. The side edges of the narrow portion 56 constitute, in effect, torquereceiving shoulders which are designed for engagement with cooperating shoulders on the key 110 and by means of which rotational motion or torque is applied to the rotatable part 16 of the barrel assembly in opposite direcions for locking and unlocking purposes in a manner that vill become clear when the nature of the key 110 is fully' lnderstood from the description hereafter.

Other details of the lock which may appear in FIGS. i, 7 and 8 bear no relation to the operation of the key .10 and, therefore, they have not been described herein.

Referring now to FIGS. 1 to 5, the key 110 which contitutes the subject matter of the present invention includes v. cylindrical key shank 112 having a relatively deep, thinvalled socket 114 in its forward end. The socket 114 is lesigned for telescopic reception over the pilot post 48 on he front end of the lock shaft 46. Projecting radially )utwardly from the wall of the socket 114 and disposed iear the extreme forward end of the shank 112 is a series )f seven radially extending fins 116 which are equally ;paced around the outer cylindrical surface of the shank and which, with the exception of one of the fins 116a, are )f equal radial extent and of equal thickness. The fin 116a is of greater radial extent than the other fins 116 and it is also of greater transverse thickness for a purpose that will appear presently. The fins 116 constitute the tumbler-operating bittings of the key. They correspond in number to and are adapted to be inserted through the aforementioned radial slots 44, there being a special radial slot 44a for the fin 116a.

The forward radial end edge of the fin 116a lies in the transverse .plane of the open rim 118 of the socket 114 while the forward radial edges of the other fins 116 lie in different transverse planes spaced rearwardly from such rim 118 and constitute tumbler-engaging shoulders so that when the key shank 112 is projected or shifted forwardly and endwise into the central opening 42 in the flange 40 and the key 116 is turned to bring the various fins 16 into longitudinal register with the forward ends of the lock tumblers,an addditionalslight forward projection or shift of the key shank will cause such depression of the tumblers 12 in the usual manner of lock operations as to bring the tumbler splits into coincidence with the interfacial plane between the aforementioned rotatable and non-rotatable parts 16 and 18 of the barrel assembly. The rear edges of the regular fins 116 and rear edge of the fin 116a preferably lie in the same transverse plane.

The rear end of the shank 112 is bifurcated by means of a relatively deep, diametrically extending, transverse notch 120. Such notch 120 receives therein the forward end region of a flat sheet metal torque-applying handle in the form of a plate 122 of generally rectangular configuration. The plate 122 is formed by a stamping operation so as to provide generally rounded corners 124 and a circular opening 126 which is located near the rear edge of the plate and by means of which the plate may be attached to a key ring or the like. The forward region of the plate 122 is formed with a rectangular recess 130 of a width substantially equal to the diameter of the cylindrical shank 112. The plate 122 fits snugly within the notch 120 with the bottom of the recess 130 lying flush against the bottom of the slot 120. A transverse locking pin 132 projects through a bore 134 in one side wall of the notch 120 and also projects through a small hole136 in the plate 122. One end of the pin 132 is received in a socket 138 in the other side wall of the notch 120. The handle-forming plate 122 is thus securely anchored in the notch 120 of the shank 112 and the exposed portions of the plate constitute a wing-type handle by means of which torque may be applied to the shank 112 so that the key may be manually turned after it has been inserted in the lock cylinder 14.

As previously stated, the various fins 116 present forward tumbler-engaging shoulders the function of which is to depress the split pin tumblers 12 when the shank 112 of the key 110 is operatively inserted into the front end of the lock cylinder 12. These fins have no other function. On the other hand, the special radial fin 116a is a torque-applying fine in that it is adapted to engage the torque-receiving shoulders that are formed by the opposite edges of the narrow slot portion 56 in the tubular" sleeve portion 52 of the rotatable part 16 of the barrel assembly. For this reason, the fin 116a is of .sturdier construction than are the fins 116, the necessary strength being afforded by making the fin 116a of greater transverse width than the fins 116 and by causing it to be of slightly greater radial extent.

Reference to FIGS. 2 and3 will disclose the fact that the various fins 116 are of relatively thin construction and are of less Width than the various radial slots 44 in the inwardly extending flange 40. The number and angular disposition of the radially extending fins 116 are precisely equal to the number and disposition ofthe radially extending slots 44, while the angular disposition of the radial fin 116a is the same as that of a radial slot 44a in said inwardly extending flange 40 on the enlarged head portions 22. The width of the slot 44a is slightly greater than that of the slots 40 so that it will accommodate passage of the fin 116a therethrough at the time the key is introduced into the central opening 42 in said flange 40. The width of the radial slots 44 is less than that of the fin 116a so that in order to gain entry into the central opening 42, the seven fins of the key must be longitudinally aligned with the seven slots in the flange 40 with the fin 116a and the slot 44a also being in longitudinal register.

In applying the key to the lock 10, the aforementioned longitudinal register between the fins 116, 116a and the slots 44, 44a is accomplished by properly aligning the key shank 112 with the lock shaft 46, after which the key is thrust or shifted forwardly in order to cause the center post 48 to enter the relatively deep socket 114 in the forward end of the key shank 112. This operation causes the fins 116 and 116a to pass through their respective slots 44 and 44a so that the key bittings of the fins 116 and the rear end edge of the fin 116a now lie completely rearwards of the flange 40. The slots 44 are out of longitudinal register with the rear ends of thesplit pin tumblers of the lock and, furthermore, the rear edge 55 of the wide portion 54 of the slot in the rotatable part 16 of the barrel assembly is disposed in the path of forward movement of the fin 116a so that the key bittings cannot be advanced forwardly until the key has been rotated in a clockwise direction as viewed in FIGS. 6- and 7 to bring the fin 116a into angular and longitudinal register with the narrow notch portion 56. When this is accomplished, the key is thrust forwardly again so that the fin 116a enterssaid narrow notch portion 56, and at the same time, the various shoulders that are afforded by the forward edges of the fins 116 (nowin register with the split pin tumblers 12) engage the front ends of the driver pins 26 and depress the same, thus'moving the split tumblers bodily rearwards and effecting transverse register of the splits 34 and freeing of the rotatable part 16 of the barrel assembly for turning movement.

As is clear from an inspection of FIG. 7, at this time.

the relatively short fins 116 which areof less radial extent than the radius of curvature of the sleeve portion 52 are totally encircled by such sleeve portion so that they are incapable of imparting torque to any portion of the rotatable part 16 of the barrel assembly. On the other hand, the radial fin 116a is of greater radial extent than the radius of curvature of the sleeve portion 52 and since it projects outwardly and completely through the narrow notch portion 56 in said sleeve portion,turning movement of the key 110 in a clockwise direction will cause the fin 116a to engage the adjacent side shoulder of the narrow notch portion 56 and apply turning movement to the rotatable part 16 of thebarrel assembly, thus turning the lock shaft 48 to its unlocking position. At such time as it is desired again to turn the shaft 48 to its locking position, counterclockwise rotation of the key 110 will cause the fin 116a to engage the other side shoulder of the narrow notchportion 56 and drive the rotatable part, and t Onsequently, the lock shaft 46, to a locking position.

It has -been previously set forth that the key shank 112 is provided with seven of the fins 16, 16a, all equiangularly spaced. This is not a matter of idle choice or design. The use of seven fins has been selected in an effort to avert unauthorized manufacture of the key 110 inasmuch as few, if any, locksmiths or tool job'bers are possessed of indexing mechanism which can be indexed throughout one-seventh of a complete revolution so that manufacture of the key by a broaching operation on cylindrical stock is rendered extremely difficult.

The invention is not to be limited to the exact arrangement of parts shown in the accompanying drawings or described in this specification as various changes in the details of construction may be resorted to without departing from the spirit or scope of the invention. Therefore, only insofar as the invention is pointed out in the accompanying claims is the same to be limited.

Having thus described the invention what I claim as new and desire to secure by Letters Patent is:

1. A key for an axial tumbler type lock, said key comprising a cylindrical shank adapted to be projected forwardly endwise into the lock opening, the forward end of the shank being formed with a thin-walled pilot socket therein presenting a circular rim opening for reception over the lock center post, an annular series of fins formed integrally on the forward end region of said shank in the vicinity of said socket, said fins being seven in number and being circumferentially spaced around the cylindrical surface of the shank and projecting raidally outwardly from the wall of the socket, six of said fins constituting tumbler-engaging fins in the form of relatively thin plate-like protuberances which lie in longitudinally extending radial planes with respect to the longitudinal axis of the shank and present radially extending forward edges variously spaced rearwardly from said circular rim of the socket and designed for engagement with the front ends of respective split tumblers associated with the lock, said six fins being of equal radial extent, the seventh fin constituting a torque-applying fin designed for sidewise engagement with a torque-receiving shoulder associated with a rotatable portion of the lock, said latter fin being of greater radial extent than the radial extent of the tumbler-engaging fins, and a torque-applying handle on the rear end region of said shank.

2. A key for an axial tumbler type lock as set forth in claim 1 and wherein said seventh fin is of greater transverse thickness than the individual tumbler-engaging fins.

3. A key for an axial tumbler type lock as set forth in claim 2 and wherein said seventh fin presents a forward radially extending edge which lies in the transverse plane of said circular rim.

References Cited by the Examiner UNITED STATES PATENTS 877,930 2/ 1908 Katzenberger -404 X 1,178,774 4/ 1916 Albright 70404 X 1,287,089 12/1918 Patterson 70-40'4 X 1,804,955 5/ 1931 Schlumpf.

MARV I N A. CHAMPION, Primary Examiner.

-P. TE-ITELBAU'M, Assistant Examiner. 

1. A KEY FOR AN AXIAL TUMBLER TYPE LOCK, SAID KEY COMPRISING A CYLINDRICAL SHANK ADAPTED TO BE PROJECTED FORWARDLY ENDWISE INTO THE LOCK OPENING, THE FORWARD END OF THE SHANK BEING FORMED WITH A THIN-WALLED PILOT SOCKET THEREIN PRESENTING A CIRCULAR RIM OPENING FOR RECEPTION OVER THE LOCK CENTER POST, AN ANNULAR SERIES OF FINS FORMED INTEGRALLY ON THE FORWARD END REGION OF SAID SHANK IN THE VICINITY OF SAID SOCKET, SAID FINS BEING SEVEN IN NUMBER AND BEING CIRCUMFERENTIALLY SPACED AROUND THE CYLINDRICAL SURFACE OF THE SHANK AND PROJECTING RAIDALLY OUTWARDLY FROM THE WALL OF THE SOCKET, SIX OF SAID FINS CONSTITUTING TUMBLER-ENGAGING FINS IN THE FORM OF RELATIVELY THIN PLATE-LIKE PROTUBERANCES WHICH LIE IN LONGITUDINALLY EXTENDING RADIAL PLANES WITH RESPECT TO THE LONGITUDINAL AXIS OF THE SHANK AND PRESENT RADIALLY EXTENDING FORWARD EDGES VARIOUSLY SPACED REARWARDLY FROM SAID CIRCULAR RIM OF THE SOCKET AND DESIGNED FOR ENGAGEMENT WITH THE FRONT ENDS OF RESPECTIVE SPLIT TUMBLERS ASSOCIATED WITH THE LOCK, SAID SIX FINS BEING OF EQUAL RADIAL EXTENT, THE SEVENTH FIN CONSTITUTING A TORQUE-APPLYING FIN DESIGNED FOR SIDEWISE ENGAGEMENT WITH A TORQUE-RECEIVING SHOULDER ASSOCIATED WITH A ROTATABLE PORTION OF THE LOCK, SAID LATTER FIN BEING OF GREATER RADIAL EXTENT THAN THE RADIAL EXTENT OF THE TUMBLER-ENGAGING FINS, AND A TORQUE-APPLYING HANDLE ON THE REAR END REGION OF SAID SHANK. 